Ultra-Endurance Associated With Moderate Exercise in Rats Induces Cerebellar Oxidative Stress and Impairs Reactive GFAP Isoform Profile.

Ultra-endurance (UE) race has been associated with brain metabolic changes, but it is still unknown which regions are vulnerable. This study investigated whether high-volume training in rodents, even under moderate intensity, can induce cerebellar oxidative and inflammatory status. Forty-five adult rats were divided into six groups according to a training period, followed or not by an exhaustion test (ET) that simulated UE: control (C), control + ET (C-ET), moderate-volume (MV) training and MV-ET, high-volume training (HV) and HV-ET. The training period was 30 (MV) and 90 (HV) min/day, 5 times/week for 3 months as a continuous running on a treadmill at a maximum velocity of 12 m/min. After 24 h, the ET was performed at 50% maximum velocities up to the animals refused to run, and then serum lactate levels were evaluated. Serum and cerebellar homogenates were obtained 24 h after ET. Serum creatine kinase (CK), lactate dehydrogenase (LDH), and corticosterone levels were assessed. Lipid peroxidation (LP), nitric oxide (NO), Interleukin 1ß (IL-1ß), and GFAP proteins, reduced and oxidized glutathione (GSH and GSSG) levels, superoxide dismutase (SOD) and catalase (CAT) activities were quantified in the cerebellum. Serum lactate concentrations were lower in MV-ET (∼20%) and HV-ET (∼40%) compared to the C-ET group. CK and corticosterone levels were increased more than ∼ twofold by HV training compared to control. ET increased CK levels in MV-ET vs. MV group (P = 0.026). HV induced higher LP levels (∼40%), but an additive effect of ET was only seen in the MV-ET group (P = 0.02). SOD activity was higher in all trained groups vs. C and C-ET (P < 0.05). CAT activity, however, was intensified only in the MV group (P < 0.02). The 50 kDa GFAP levels were enhanced in C-ET and MV-ET vs. respective controls, while 42 kDa (∼40%) and 39 kDa (∼26%) isoform levels were reduced. In the HV-ET group, the 50 KDa isoform amount was reduced ∼40-60% compared to the other groups and the 39 KDa isoform, increased sevenfold. LDH levels, GSH/GSSG ratio, and NO production were not modified. ET elevated IL-1ß levels in the CT and MV groups. Data shows that cerebellar resilience to oxidative damage may be maintained under moderate-volume training, but it is reduced by UE running. High-volume training per se provoked systemic metabolic changes, cerebellar lipid peroxidation, and unbalanced enzymatic antioxidant resource. UE after high-volume training modified the GFAP isoform profile suggesting impaired astrocyte reactivity in the cerebellum.

Efficacy of tubing technique with biomaterials compared to direct coaptation technique after peripheral neurotmesis in nerve healing and return to functionality in young adult rats: a systematic review protocol.

BACKGROUND: Peripheral nerves are constant targets of traumatic injury which may result in neurotmesis and which invariably requires surgical treatment. In view of this, tissue engineering studies developed biomaterials which were first tested in animal models and used as a guide for nerve stumps in the procedure in order to speed up the healing process. Therefore, the aim of this study is to evaluate the efficacy of biomaterials used in tubing technique on healing and histological and functional recovery after peripheral nerve neurotmesis in rats. METHODS: We will search PubMed/MEDLINE, Embase, Web of Science, LILACS, and CENTRAL (from inception onwards). Grey literature will be identified through searching dissertation databases, guidelines, policy documents, and reports. We will include randomized and non-randomized trials conducted in young adult rats with peripheral neurometsis undergoing surgical repair through tubing technique with biomaterials. Primary outcomes will be histomorphometry, immunohistochemistry of the nerve tissue, and sciatic functional index. Secondary outcome will be nerve macroscopic evaluation. Two reviewers will independently screen all citations, full-text articles, and abstract data. Potential conflicts will be resolved through discussion. The methodological quality (or risk of bias) of individual studies will be appraised using an appropriate tool. If feasible, we will conduct random effects meta-analysis. DISCUSSION: This systematic review of animal studies will identify, evaluate, and synthetize the evidence on the the efficacy of tubing technique with biomaterials compared to direct coaptation technique after peripheral neurotmesis in nerve healing and return to functionality. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42018106042.

Endurance training on rodent brain antioxidant capacity: A meta-analysis.

The influence of physical exercise on brain antioxidant defense mechanisms has been studied. Nevertheless, the effect of training volume on the brain`s redox balance remains unclear. In this meta-analysis, we compared the effect of training volume on antioxidant enzymatic resource and lipid peroxidation on various brain regions. The activities of the enzymes glutathione peroxidase (GPx), superoxide dismutase (SOD), catalase (CAT) and the levels of thiobarbituric acid reactive substances (TBARS) were also evaluated. The effects of training periods (weeks) and exercise duration were compared. Meta-analysis revealed that protocols over 8 weeks were associated with an increase in SOD (p = 0.0008) and CAT activities (p = 0.0001). Exercise durations for 30 and 60 min were associated with higher CAT activity (p = 0.04). Joint analysis revealed that moderate physical exercise over 4 and 8 weeks promoted a healthy enzymatic balance. However, high volumes of exercise over 8 weeks were associated with the increased antioxidant enzymatic activity, indicating higher reactive oxygen species (ROS) levels. The data also indicated that there is still limited research and inaccurate information, on the safety conditions of training periods that simulate tests of ultra resistance in humans.

Sugarcane biopolymer as a guide tube in the regeneration of peripheral nerves in rats / Biopolímero de caña de azúcar como tubo guía en la regeneración de nervios periféricos en ratones

SUMMARY: Peripheral nerve regeneration is a serious clinical problem. The goal of this work was to evaluate comparatively a biopolymer tube of sugarcane with an expanded polyethylene tube as a tube guide in peripheral nerve regeneration. Fourteen male albino Wistar rats were used, separated into three different groups: control (CG), lesion + polyethylene tube (PG) and lesion + sugarcane biopolymer (SBG). At 60 days old, animals from the PG and SBG underwent surgery for tubulization of the sciatic nerve, and 60 days after the injury they were sacrificed for collection of the nerve. In the analysis of the number of nerve fibers, a smaller number was seen in the PG and SBG groups compared to the CG, no difference was seen between the PG and SBG groups (p<0.05). With regard to the number of blood vessels, the SBG group had a larger number than the CG and PG groups (p<0.05). The SBG also presented increase on axonal diameter and G -ratio compared to PG (p<0.05). Taken together these data revealed that biopolymer tube favors a suitable environment for peripheral nerve regeneration.

RESUMEN: La regeneración nerviosa periférica es un problema clínico grave. El objetivo de este trabajo fue evaluar comparativamente un tubo de biopolímero de caña de azúcar con un tubo de polietileno expandido, como guía de tubo en la regeneración de nervios periféricos. Se utilizaron dieciocho ratas Wistar albinas macho, separadas en tres grupos: control (CG), lesión + tubo de polietileno (PG) y lesión + biopolímero de caña de azúcar (SBG). A los 60 días de edad, los animales del PG y SBG fueron sometidos a una cirugía para la tubulización del nervio ciático, y 60 días después de la lesión fueron sacrificados para la recolección del nervio. En el análisis del número de fibras nerviosas, se observó un número menor en los grupos PG y SBG en comparación con el CG; no se observaron diferencias entre los grupos PG y SBG (p <0,05). Con respecto al número de vasos sanguíneos, el grupo SBG tuvo un número mayor que los grupos CG y PG (p <0,05). El SBG también presentó un aumento en el diámetro axonal y la proporción G en comparación con PG (p <0,05). En conjunto, estos datos revelaron que el tubo de biopolímero favorece un entorno adecuado para la regeneración de nervios periféricos.

Quadriceps muscle architecture ultrasonography of individuals with type 2 diabetes: Reliability and applicability.

Muscle architecture parameters performed using ultrasound serve as an aid to monitor muscle changes derived from diseases, however there are no studies that determine the reliability and applicability of this evaluation in individuals with type 2 diabetes (DM2). Three raters captured three images of measurements of thickness of the rectus femoris (RF), vastus intermedius and anterior quadriceps, RF muscle cross-sectional area, RF pennation angle in 17 individuals with DM2 above 50 and sedentary. Intra and inter-raters analysis showed reliability from high to very high for the three raters (ICC> 0.87), except for the RF pennation angle with moderate to low intra-raters (ICC = 0.58, 0.48, 0.51), and high inter-rater reliability (ICC = 0.70). Ultrasound measurements of quadriceps muscles showed high to very high intra and inter-raters reliability, thus allowing its use to monitor muscle changes provoked by diabetes or interventions in individuals with DM2.

Previous physical exercise slows down the complications from experimental diabetes in the calcaneal tendon.

BACKGROUND: the complications caused by diabetes increase fragility in the muscle-tendon system, resulting in degeneration and easier rupture. To avoid this issue, therapies that increase the metabolism of glucose by the body, with physical activity, have been used after the confirmation of diabetes. We evaluate the biomechanical behavior of the calcaneal tendon and the metabolic parameters in rats induced to experimental diabetes and submitted to pre- and post-induction exercise. METHODS: 54-male-Wistar rats were randomly divided into four groups: Control Group (CG), Swimming Group (SG), Diabetic Group (DG), and Diabetic Swimming Group (DSG). The trained groups were submitted to swimming exercise, while unexercised groups remained restricted to the cages. Metabolic and biomechanical parameters were assessed. RESULTS: the clinical parameters of DSG showed no change due to exercise protocol. The tendon analysis of the DSG showed increased values for the elastic modulus (p<0.01) and maximum tension (p<0.001) and lowest value for transverse area (p<0.001) when compared to the SG, however it showed no difference when compared to DG. CONCLUSION: the homogeneous values presented by the tendons of the DG and DSG show that physical exercise applied in the pre- and post-induction wasn't enough to promote a protective effect against the tendinopathy process, but prevent the progress of degeneration.

Normalization patterns of the surface electromyographic signal in the phonation evaluation.

PURPOSE: The aim of the study was to compare the different parameters, regarding the peak and mean, at different phonatory tasks for standardization of electromyography signal of electrical activity (EA) of the laryngeal extrinsic muscles on voice evaluation. METHODS: The electrical potentials of the suprahyoid (SH) and infrahyoid (IH) muscles of 35 voluntary nondysphonic subjects were evaluated using three evaluations of rest, two maneuvers to determine maximum voluntary sustained activity (MVSA), and usual and strong intensity of vowel /ɛ/ and 20-30 count emissions. The EA signal was converted using root mean square in microvolts and normalized by mean and peak of each task. The selected normalization task was that with minor coefficient of variation for all muscles. RESULTS: The tasks that provided minor coefficient of variation of EA in both muscle groups were the peak of vowel /ɛ/ (mean potentials equal to 43.31 ± 2.97 for right IH, 36.27 ± 2.76 for left IH, and 42.11 ± 2.57 for SH) and the 20-30 count emissions (mean potentials equal to 31.30 ± 308 for right IH, 30.56 ± 2.76 for left IH, and 30.43 ± 4.22 for SH), both in usual intensity and MVSA, as second option. CONCLUSIONS: The peak of vowel /ɛ/ and 20-30 count emissions is usual intensity, and the MVSA as second option should be considered for signal normalization in SH and IH muscles, and may provide conditions for using the surface electromyography in voice clinic.

Is swimming able to maintain bone health and to minimize postmenopausal bone resorption?

OBJECTIVE: We studied the effect of swimming on the somatic and bone growth of female rats. METHODS: 40 neonate Wistar female rats were separated into: monosodium glutamate group (GluM, n = 20) and received MSG solution (4.0 mg/g) on alternate days during the first 14 days after birth, and Saline group (SAL, n = 20) which received saline solution for the same period of time and at the same dose.At 60 days of age, GluM group was ovariectomized (GluMO) and SAL group just suffered surgical stress. Subsequently, half the animals in each group started swimming, resulting in groups: sedentary saline (SALsed, n = 10), swimming saline (SALswi, n = 10), sedentary ovariectomized Glutamate (GluMOsed, n = 10) and swimming ovariectomized Glutamate (GluMOswi, n = 10). At the end of the experiment, we measured the animals' longitudinal length and weight; their radius was weighed and its length measured. RESULTS: The animals of the GluMOsed group had lower body weight and longitudinal length compared to SALsed. Swimming decreased body weight, but had no influence on the longitudinal length of the GluMOswi group compared to GluMOsed group. Longitudinal length and body weight were lower in SALswi animals compared to SALsed animals. Radius weight and length of GluMOsed animals were lower than in SALsed animals. There was no difference in these parameters between GluMOsed and GluMOswi groups; however, these parameters were lower in SALswi animals compared to SALsed animals. CONCLUSION: Swimming does not influence previously affected bone tissue during the neonatal period, however it may cause damage to healthy bone tissue.

Impact of early malnourishment on the chronic inflammatory response and its implications for the effect of indomethacin on Wistar rats.

The objective of the present study was to investigate whether early undernutrition changes the chronic inflammatory response, so as to study its influence on pharmacological response to indomethacin. Rat offspring of dams fed from the first day of gestation to term or throughout the lactation period received a balanced diet (NN) or a basic regional diet (BRD) from northeast Brazil. According to their dams, the offspring were divided into three groups: NN; basic regional diet during gestation (BRD-g, undernourished during gestation); basic regional diet during gestation and lactation (BRD-gl, undernourished during gestation and lactation). At 2 months of age, Freund's adjuvant (0·2 ml) was inoculated into the plantar surface of the hind paw (day 0) of animals. All animals orally received saline (0·9 %) for 28 d. Another group of adult offspring was subjected to the same procedure as described above, but orally received indomethacin (2 mg/kg) instead of saline, and divided into three subgroups: NN treated with indomethacin (NNI); BRD-g treated with indomethacin (BRDI-g); BRD-gl treated with indomethacin (BRDI-gl). The hind paw volume was calculated on days 0 (initial paw volume), 7, 14 and 28. Hind paw swelling, blood albumin and C-reactive protein (CRP) levels and leucocyte counts were evaluated as markers of inflammation. Reduced hind paw swelling and the blood levels of serum albumin and CRP were found in the BRD-g and BRD-gl offspring. However, no difference was found in the leucocyte count. Compared with their respective saline-treated groups (NN, BRD-g and BRD-gl), the anti-inflammatory effect of indomethacin was lower in the BRDI-g and BRDI-gl groups than in the NNI group. We conclude that early undernutrition attenuated the chronic inflammatory response and the anti-inflammatory effect of indomethacin.

Mechanical properties of achilles tendon in rats induced to experimental diabetes.

The aim of this study was to quantify the effect of chemically induced diabetes mellitus (DM) on the mechanical properties of the Achilles tendon of rats and correlate it with metabolic and biomechanical findings. Adult rats were selected randomly and assigned to two groups, the diabetic group consisted of animals receiving a dose of streptozotocin to induce type I diabetes and the control group. The animals were placed in metabolic cages for analysis of metabolism. Ten weeks after diabetes induction, the Achilles tendon of both groups were collected and submitted to a traction test in a conventional testing machine. The measurements of mechanical properties indicated that the elastic modulus (MPa) was significantly higher in the control group (p < 0.01). In Maximum tension (MPa), the groups did not have differences (p > 0.01). Energy/tendon area (N mm/mm²), specific strain (%) and maximum specific strain (mm) were higher in tendon tests of the diabetic group (p < 0.01). We observed that the mechanical properties of tendons have correlations with metabolic properties of the diabetic animals. These results showed that induced DM in rats have an important negative effect on the mechanical properties of the Achilles tendon.

Do malnutrition and fluoxetine neonatal treatment program alterations in heart morphology?

Growth and development events are observed in all organisms and can be modified by exogenous factors such as nutritional changes. Drastic morphological and functional alterations may occur during a vulnerable stage of development. The aim of this study was to investigate if malnutrition and/or fluoxetine neonatal treatment program alterations in heart morphology during the postnatal period. The sample consisted of 48 albino Wistar male rats. The rats were divided into two groups: nourished and malnourished. Pharmacologic manipulation was performed during the suckling period. The animals of each group were divided into two subgroups: saline-nourished and saline-malnourished, treated with sodium chloride solution, and fluoxetine-nourished and fluoxetine-malnourished, treated with fluoxetine. Half of the individuals in each subgroup were weighed and sacrificed on day 30 and the other half on day 71. Myocardial perfusion was performed and the heart subsequently weighed. The ventricles were cross-sectioned into two parts, which were fixed, dehydrated and sectioned. There were differences in body weight, heart weight, cross-sectional area and perimeter of the heart and in the cross-sectional area and perimeter of the cardiac cells among the groups at the different ages. Malnutrition appears to program alterations in heart morphology. However, malnourished animals that had undergone drug treatment did not exhibit the same changes.

[The effect of endurance training on the neovascularization of skeletal musculature]. / Efeito do treinamento de endurance sobre a neovascularização da musculatura esquelética.

PURPOSE: To quantify the capillaries in the skeletal muscular tissue of mice with induced peripheral arterial insufficiency, after endurance training. METHOD: It was used Wistar mice in 70 days age range, subjected to the total occlusion of right femoral artery. The animals were divided into two groups: sedentary group (SG; n = 05), subjected to activities in the cage; and trained group (TG; n = 05), subjected to an endurance training in cycle ergometer twice a day 17m/min, by 5 minutes, 5 days per week during 10 weeks. The analysis was realized by the histologic observation of the vastus medialis muscle of injured member. RESULTS: The average number of capillaries in the muscular tissue was greater in TG (5,2 +/- 0,83) than in SG (1,6 +/- 1,14) (p < 0,05). CONCLUSION: In animals with induction of peripheral arterial insufficiency, the endurance training provides a process of muscular adaptation which is observed by the increase in the number of capillaries of animals subjected to this kind of training.

[Morphometry of human myocardium in senile individuals]. / Morfometria do miocárdio humano em indivíduos senis.

OBJECTIVE: To carry out a quantitative assessment in human myocardium cells of senile individuals, in right, left and septal ventricular regions. METHODS: Five hearts from corpses of individuals without heart diseases, of both sexes, with age between 67 and 87 years old were used. The following parameters were assessed: myocyte unit cross section area (myoc. a(o)); myocyte unit perimeter length (myoc. l(o)); myocyte unit volume (myoc. v(o)); myocyte volumetric density (myoc. V(v)); number of myocytes per volume unit (Nmm 3myoc.). The t-test of Student was used in statistic analysis. RESULTS: The analysis of differences (p < 0.05) among right (RV), left (LV) and septal (S) ventricular regions of human heart showed that myoc. a(o) values were lower in RV (1.51 +/- 0.10 microm2) and in S (1.55 +/- 0.07 microm2) in relation to LV (1.84 +/- 0.24 microm2). Values of myoc. l(o) were also shown lower in S (5.11 +/- 0.46 microm) comparing to LV (6.2 +/- 0.97 microm). Likewise, myoc. v(o) and myoc. V(v) showed lower values in RV (88.75 +/- 25.37 microm3; 0.39 +/- 0.03%) in relation to LV (122.41 +/- 16.31 microm3; 0.41 +/- 0.01%). CONCLUSION: Results obtained show that there may be changes in dimensions of left ventricular wall myocyte cell during senescent stage. However, those differences are subtle and seem to mean the adjustment of tissue to functional changes that install along life.